The choroid is a layer of blood vessels and connective tissue located between the retina and the sclera in the eye. It plays a crucial role in providing oxygen and nutrients to the outer layers of the retina, which is essential for maintaining healthy vision. The choroid is rich in melanin, which helps absorb excess light and reduces glare. In addition to its supportive functions, the choroid also contains cells that can help regulate the temperature of the eye. This layer is part of the uveal tract, which also includes the iris and ciliary body, contributing to the overall health and function of the human eye.